[12p-PA3-1~33] 11 Superconductivity

▲ [12p-PA3-10] First-principles study of high temperature superconductivity of compressed YKH₁₂

〇(M2)Peng Song^1,2, Hou Zhufeng³, Yoshihiko Takano^1,2 (1.NIMS, 2.Univ. of Tsukuba, 3.CAS)

Keywords:superconductivity, hydrogen-rich material

Recently, with the successful discovery of superconductivity in LaH₁₀(~260 K at ~200 GPa )[1] and H₃S(~200 K at ~200 GPa )[2] by experiment, metal hydrides have contributed more and more to the study of high temperature superconductivity (HTSC). The search for superconducting metal-hydride at very high pressures has long been viewed as a key problem in physics. Many researchers have conducted extensive research on binary hydrogen-rich compounds involving the binding of most elements of the periodic table to hydrogen. More than 60% of the binary metal hydrides over the Mendeleev’s Periodic Table have been shown superconductivity. The ternary or multi-component hydrides have become the ideal playground to discover HSTC. Recently, the superconductivity in Li₂MgH₁₂[3] was found and shown an ultra-high critical temperature of 473 K (200 GPa) by structure prediction.
In this work, we extensively performed structure search for the high-pressure phase and superconductivity of YKH₁₂ using the evolutionary algorithm structure prediction method and first-principles calculations. The results showed that YKH₁₂ became stable at 150 GPa and had a C2/m structure. And its stability will increase with the increase of pressure, and the second stable phase P2₁/m appears above 270 GPa. Electron-phonon coupling calculations show that YKH₁₂-C2/m is a potential high-temperature superconductor, with a Tc of 145 K at 200 GPa. YKH₁₂ can be regarded as a combination of YH₆ and KH₆, so our current research provides the possibility to find new high temperature superconducting ternary hydrides.